[GCM] Start GCMChannelStatusSyncer when GCM is disabled

components/gcm_driver/gcm_driver_desktop.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/gcm_driver/gcm_driver_desktop.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
@@ skipping 409 matching lines @@
 
    // Ensures that the GCM service is started when there is an interest.
   EnsureStarted();
 }
 
 void GCMDriverDesktop::RemoveAppHandler(const std::string& app_id) {
   DCHECK(ui_thread_->RunsTasksOnCurrentThread());
   GCMDriver::RemoveAppHandler(app_id);
 
   // Stops the GCM service when no app intends to consume it.
-  if (app_handlers().empty())
+  if (app_handlers().empty()) {
     Stop();
+    gcm_channel_status_syncer_->Stop();
+  }
 }
 
 void GCMDriverDesktop::AddConnectionObserver(GCMConnectionObserver* observer) {
   connection_observer_list_.AddObserver(observer);
 }
 
 void GCMDriverDesktop::RemoveConnectionObserver(
     GCMConnectionObserver* observer) {
   connection_observer_list_.RemoveObserver(observer);
 }
@@ skipping 18 matching lines @@
   Stop();
 }
 
 void GCMDriverDesktop::Stop() {
   DCHECK(ui_thread_->RunsTasksOnCurrentThread());
 
   // No need to stop GCM service if not started yet.
   if (!gcm_started_)
     return;
 
-  gcm_channel_status_syncer_->Stop();
-
   RemoveCachedData();
 
   io_thread_->PostTask(
       FROM_HERE,
       base::Bind(&GCMDriverDesktop::IOWorker::Stop,
                  base::Unretained(io_worker_.get())));
 }
 
 void GCMDriverDesktop::RegisterImpl(
     const std::string& app_id,
@@ skipping 152 matching lines @@
                  base::Unretained(io_worker_.get()),
                  account_tokens));
 }
 
 GCMClient::Result GCMDriverDesktop::EnsureStarted() {
   DCHECK(ui_thread_->RunsTasksOnCurrentThread());
 
   if (gcm_started_)
     return GCMClient::SUCCESS;
 
-  if (!gcm_enabled_)
+  if (!gcm_enabled_) {
+    // Poll for channel status in order to find out when it is re-enabled when
+    // GCM is currently disabled.
+    if (GCMDriver::IsAllowedForAllUsers())
+      gcm_channel_status_syncer_->EnsureStarted();
+
     return GCMClient::GCM_DISABLED;
+  }
 
   // Have any app requested the service?
   if (app_handlers().empty())
     return GCMClient::UNKNOWN_ERROR;
 
   // TODO(jianli): To be removed when sign-in enforcement is dropped.
   if (!signed_in_ && !GCMDriver::IsAllowedForAllUsers())
     return GCMClient::NOT_SIGNED_IN;
 
   DCHECK(!delayed_task_controller_);
@@ skipping 114 matching lines @@
 
   // Normally request_gcm_statistics_callback_ would not be null.
   if (!request_gcm_statistics_callback_.is_null())
     request_gcm_statistics_callback_.Run(stats);
   else
     LOG(WARNING) << "request_gcm_statistics_callback_ is NULL.";
 }
 
 }  // namespace gcm